Vat dye and process of making same.



UNITED STATES FATE NT OliFlCE.

HERMANN KRAFT, OF BASEL, EWITZERLA1 lD ASSIGNOR TO SOCIETY OF CHEMICALINDUSTRY IN BASLE, 0F BASEL, SWITZJEIRLAND.

VAT DYE AND PROCESS OF MAKING SAME.

No Drawing.

Specification of Letters Patent.

Application filed April 1, 1909.

Patented Nov. 23, 1909. Serial No. 487,275.

To all whom it may concern:

Be it known that I, llnmmxx KnAi-r,d ctor ot philosophy and chemist, asubject of the Emperor of Austria-Hungary, and resident of Basel,Switzerland, have invented new and useful Vat Dyestuiis and a Process ofMaking Same, of which the following is a. full, clear, and exactspecification.

I have found that by condensing halogensubstituted isatin derivatives ofthe naphthalene series with 3-oxy l-thionaphthene new at-dyestuffs ofthe thioindigo series: are obtained, which dye cotton brown-violet andviolet-gray to violet-black shades. The manufacture of these dyestutl'sis illustrated by the following examples.

Example I. 4.5 parts of monobromobetanaphthisatin chlorid (obtained bytreating monobromobetanaphthisatin with phosphorus pentachlorid), 2.3parts of oxythionaphthcne and parts of xylene are boiled together forhour. The solution assumes a violet coloration and while hydrochloricacid is split off a reddish black, crystalline condensationproductseparates. The said product is recovered by filtration and washedwith alcohol. It dissolves in benzene and in nit-robenzene with a redviolet coloration. Its solution in concentrated sulfuric acid is dirtygreen. lVith alkaline reducing agents it yields a deep orange vat dyeingcotton deep gray to Violet black tints of excellent fastness.

Example II. 35.5 parts of dibromobetanaphthisatin melting at 300 C.(prepared for instance by brominating betanaphthisatin in nitrobenzenein the heat) and 15 parts of 8-oxy-l-thionaphthene are heated togetherwith 250 parts of nitrobenzene for 1% to 2 hours in an oil bath to210-J30 C. After cooling, the condensation product is sepa rated byfiltration, washed with alcohol and dried. The so obtained deepbrown-red crystalline powder dissolves in concentrated sulfuric acid toa. greenish blue solution. It dissolves diflicultly in hot benzene andin alcohol with red coloration and easily in hot nitrobenzene with acherry-red coloration. In order to permit an easier preparation of a vatwith the dyestufi', the latter is advantageously iirst treated with analcoholi 1 alkali sulfhydral'e, which dissolves the said dyestufi' to agreen-yellow solution from which the dyestufi' is again blown out withair as a paste directly employed for dyeing. It dyes cotton from analkaline vat gray- \'iolet tints of a good fastness to washing, light.and chlorin.

If in the foregoing example, there is substituted for theclibromobetanaphthisatin broinoalphanaphthisatin melting at 286- 287 0.(obtained by broniinating alphanaphthisatin in glacial acetic acid inthe heat) there is obtained a dyestuii dyeing cotton from an alkalinevat brown-violet shades fast to washing, light and chlorin.

Example III, 37.3 parts of dibroinobetanapht-hisat-in chlorid(obtainable by treating dibromobetanaphthisatin with phosphoruspentachlorid in presence of an indifferent diluting agent as forinstance pentachlorethane) and 15 parts of 3-oxy-l-thio naphthene areboiled with 300 to 400 parts of xylene for about 1 hour. After a shorttime, the reaction takes place and the solution assumes a cherry-redcoloration while the dyestuif separates. It is isolated by filtration,washed with alcohol and dried. The condensation product constitutes abrownred powder and yields with sodium hydrosulfite a brownish coloredvat dyeing cotton violet-gray tints of excellent fastness to washing,light and chlorin.

What I claim is:

1. The described process for the manufacture of halogcnizedvat-dyestuffs of the thioindigo series, which consists in condensing 111101. of a halogen substituted isatin derivative of the naphthaleneseries with 1 mol. of 3-0xy-1-thionaphthene.

2. The described process for the 1nanufacture of halogenizedeat-dyestuffs of the tideindigo series, which consists in condensing 111101. of a brominated naphthisatin with 1 mol. of3-oXy-l-tl1ionaphthene.

3. As new products, the described halogenized vat dyestufi's, derivedfrom a halo genated naphthisatin and 3 oxy-l-thionaphthcne, andconstituting in dry state brownish-red powders soluble in concen- Inwitness whereof I have hereunto signed my name this 20th day of March1909, in the presence of (we subscribing witnesses.

HERMANN KRAFT.

\Vitnesses:

G120. Gmronn, Anxow ZUBEIK.

Correction in Letters Patent No. 941,152;

It is hereby certified that in Letters Patent No. 941,152, grantedNovember 23,

1909, upon the application of Hermann Kraft, of Basel, Switzerland, foran improvement in Vat Dyes and Processes of Making Seine, an errorappears in the printed specification requiring correction, as follows:Page 1, line 92, the compound word cat-dyestuffs should readvat-dyestufi; and that the said Letters Patent should be read with thiscorrection therein that the same may conform to the record of the easein the Patent Oflice.

Signed and sealed this 25th day of January, A. 1)., 1910.

[smu] U. G. BILLINGS,

Actim Uommzksz'orier 0 l dt'rns.

